Last time I saw those, it didnt have Trijicon's name on them. It was bushnell or of Hong Kong brand. Tasco or something. I wonder if the Trij is stronger if it has its name on it?
As the owner stated, it is completely legal and no different than an HK94/93/91 with a lower group that has full-auto markings. If you're interested in the process there are tons of threads here describing the process. There are some modifications that need to be done for the lower to fit on the upper, for the UMP mags to fit in the upper, and a stock block to hold the upper, lower, and stock together. There are even modifications that can be done to UMP 40 and 9 bolts to make them fit in the USC upper.Is this a NFA legal conversion? I didn't think UMP's could be owned by us regular people.